Maximum length of a URL

What is the maximum length of a URL?

Although the specification of the HTTP protocol does not specify any maximum length, practical limits are imposed by web browser and server software.

Microsoft Internet Explorer (Browser)
Microsoft states that the maximum length of a URL in Internet Explorer is 2,083 characters, with no more than 2,048 characters in the path portion of the URL. URLs longer than this produced a clear error message in Internet Explorer.

Firefox (Browser)
After 65,536 characters, the location bar no longer displays the URL in Windows Firefox 1.5.x. However, longer URLs will work. Just try testing 100,000 characters.

Safari (Browser)
At least 80,000 characters will work.

Opera (Browser)
At least 190,000 characters will work. Opera 9 for Windows continued to display a fully editable, copyable and pasteable URL in the location bar even at 190,000 characters.

Apache (Server)
Maximum URL length limit of approximately 4,000 characters, after which Apache produces a "413 Entity Too Large" error.

Microsoft Internet Information Server
The default limit is 16,384 characters (yes, Microsoft's web server accepts longer URLs than Microsoft's web browser). This is configurable.

Perl HTTP:aemon (Server)
Up to 8,000 bytes will work.